Association of depression and epilepsy in Rwanda: A prospective longitudinal study.

Introduction: Depression is the most common psychiatric comorbidity for persons living with epilepsy. In Rwanda, the prevalence of epilepsy and depression are high, with 4,9% and 13.0% respectively. This prospective interventional study aimed to determine the prevalence and incidence of depression and the outcome of persons living with epilepsy (PwE) with depression attending the outpatient neurology department of a tertiary center.

Methods: Persons living with epilepsy enrolled between February and June 2018 in a screening cohort with a 12-month follow-up. At every 3-month study visit, PwE were screened for depression using the Patient Health Questionnaire (PHQ-9) questionnaire. Any positively screened subject was administered the Hamilton Depression Rating Scale (HDRS) to confirm the diagnosis and severity of depression. Subjects with moderate to severe depression (MSD), were started on treatment and were followed for another year. We describe the prevalence and incidence of depression, baseline characteristics, epilepsy and depression outcomes, and changes in PGI-C.

Results: Of 572 PwE enrolled, 46 were diagnosed with MSD in a twelve-month period, resulting in an incidence of MSD of 32.7/1000 patient-years. The prevalence of any depression and MSD was 14.2% and 4.7%, respectively. Longer epilepsy duration and seizure status at baseline were associated with MSD. Significant improvements in PGI-C and seizure frequency were observed after treatment optimization.

Conclusion: The use of PHQ-9 and HDRS proved successful in identifying depression in PwE. Combined treatment of epilepsy and depression resulted in improved outcomes, warranting the implementation of depression screening every six months in daily neurology practice.